Flaked graphite has recently attracted attention as a substance having a carbon skeleton and high shape anisotropy. Flaked graphite is obtained by separating graphene sheets from graphite. Due to its high hardness, flaked graphite can be expected to act as a reinforcing material when mixed with a synthetic resin. Graphene sheets are separated from graphite multiple times to provide the flaked graphite having a high specific surface area. Therefore, the amount of flaked graphite required to be added can be decreased. This may minimize various risks usually associated with a synthetic resin containing flaked graphite, such as increased specific gravity and loss of brittleness. Furthermore, flaked graphite is also expected to affect the expression of various functions. For this reason, flaked graphite has been widely studied in various fields.
In contrast, polyolefin-based resins can be easily handled from the viewpoint of moldability, cost of distribution and impact on the environment, and have been used widely. However, polyolefin-based resins often do not have the mechanical and physical properties required for various applications. In order to obtain a polyolefin-based resin composition having excellent mechanical and physical properties such as rigidity, strength, and shock resistance, a variety of studies have been undertaken.
For example, in order to provide a resin composition having excellent mechanical and physical properties such as rigidity and shock resistance and excellent moldability, Patent Literature 1 discloses a resin composition containing a fibrous filler having an average particle diameter of 0.1 to 30 μm and an aspect ratio of 20 to 80, an inorganic nanofiller having an average particle diameter of 300 nm or less, and a polypropylene resin.
Further to this, examples detailed in Patent Document 1 describe a composition containing polypropylene, fine nano-scale silica particles, and glass fibers, where the composition has excellent moldability and good surface appearance, and the bending modulus and the impact test results are both improved. Moreover, Patent Literature 1 describes that the resin composition can be used for the exterior panels of automobiles. However, Patent Literature 1 does not describe significant physical values such as the modulus of elongation and coefficient of linear expansion of the resin composition.
The resin composition described above contains a fibrous filler, and the fibrous filler has the disadvantage of being difficult to handle. In addition, a molded product formed using the resin composition displays surface deterioration.